Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan.
Department of Neurosurgery, Henry Ford Health System, Detroit, Michigan.
Pract Radiat Oncol. 2017 Nov-Dec;7(6):e409-e417. doi: 10.1016/j.prro.2017.05.007. Epub 2017 May 25.
To determine the potential benefits and adverse effects associated with reirradiating the spinal cord when at least 1 course of radiation therapy (RT) is stereotactic radiosurgery (SRS).
This institutional review board-approved retrospective review included 162 patients (237 reirradiated spine lesions). All patients received SRS at our institution between 2001 and 2013. Electronic medical records were reviewed for clinical exams and radiologic tests (computed tomography/magnetic resonance imaging). Primary endpoints were pain, neurological, radiographic responses, and the development of adverse effects.
A total of 120 patients (74.1%) were deceased with a median survival of 13 months. Time between courses of RT was a median of 10.2 months. Median SRS dose was 16 Gy in 1 fraction, whereas the median conventional external beam radiation therapy (cEBRT) dose was 30 Gy in 10 fractions. The median tumor equivalent dose in 2-Gy fractions (EQD2) for SRS doses was 34.7 Gy, whereas the median tumor EQD2 for cEBRT was 32.5 Gy, providing a median total tumor EQD2 of 69.3 Gy (22-145.6 Gy). The median critical nervous tissue EQD2 for SRS and cEBRT was 56 Gy and 37.5 Gy, respectively, resulting in a median total critical nervous tissue EQD2 of 93.5 Gy. Overall pain, neurological, and radiographic response rates were 81%, 82%, and 71%, respectively. Adverse effects occurred in 11 (6.8%) patients. Seventy-seven vertebral compression fractures were observed, 22 (9.3%) of which may be attributed to RT.
Our results demonstrate that reirradiation achieves favorable response rates with minimal toxicity if recommended dose constraints to the spinal cord with SRS are carefully observed. To the best of our knowledge, this is the largest reported single-institution experience analyzing the efficacy and toxicity of reirradiation of the spine when at least 1 course of RT is stereotactic radiosurgery.
确定在至少进行过 1 次放射治疗（RT）的情况下，对脊髓进行再放射治疗的潜在益处和不良反应。
这项经机构审查委员会批准的回顾性研究纳入了 162 名患者（237 个再放疗脊柱病变）。所有患者均于 2001 年至 2013 年在我院接受立体定向放射外科治疗（SRS）。对电子病历进行了临床检查和影像学检查（计算机断层扫描/磁共振成像）的回顾。主要终点为疼痛、神经学、影像学反应以及不良反应的发生情况。
共有 120 名（74.1%）患者死亡，中位生存期为 13 个月。两次 RT 之间的时间间隔中位数为 10.2 个月。SRS 单次分割剂量中位数为 16 Gy，而常规外照射放疗（cEBRT）的中位数剂量为 30 Gy，分割 10 次。SRS 剂量的 2-Gy 等效剂量（EQD2）中位数肿瘤剂量为 34.7 Gy，而 cEBRT 的 EQD2 中位数肿瘤剂量为 32.5 Gy，总肿瘤 EQD2 中位数为 69.3 Gy（22-145.6 Gy）。SRS 和 cEBRT 的中位关键神经组织 EQD2 分别为 56 Gy 和 37.5 Gy，总关键神经组织 EQD2 中位数为 93.5 Gy。总体疼痛、神经学和影像学反应率分别为 81%、82%和 71%。11 名（6.8%）患者出现不良反应。共观察到 77 例椎体压缩性骨折，其中 22 例（9.3%）可能归因于 RT。
如果仔细观察 SRS 对脊髓的推荐剂量限制，我们的研究结果表明再放疗可获得良好的反应率，且毒性最小。据我们所知，这是目前报道的最大的单一机构经验，分析了至少进行过 1 次立体定向放射外科治疗的情况下，对脊柱进行再放疗的疗效和毒性。
